Rapists and abusers are escaping justice in Britain's south Asian communities as sexual and domestic violence is going unreported by women and children who are trapped in a pervasive culture of shame, according to a new academic study.

The research project, carried out across several counties in England and Wales, has found that a lack of awareness about what constitutes criminal behaviour is endemic among first generation immigrant families from Pakistan, Bangladesh and India.

"There was certainly no awareness that there could be rape within a marriage," said Dr Karen Harrison of Hull University who, with co-author Dr Aisha Gill of the University of Roehampton, has carried out a two-year project talking to women, charities, police officers and religious leaders and holding focus groups.